Evaluation of 18F-FDG PET with bladder irrigation in patients with uterine and ovarian tumors.

The purpose of this study was to evaluate PET using (18)F-FDG for gynecologic lesions with continuous bladder irrigation to eliminate artifacts from the (18)F-FDG activity in the bladder. METHODS: Forty-one patients were studied. They had 23 cervical uterine lesions (15 cases of cancer, 5 recurrences, 3 nonrecurrences); 8 cases of uterine corpus cancer, including 2 recurrences; and 10 ovarian masses (6 malignant, 4 nonmalignant). All cases of cancer were histologically proven; however, 2 cases of nonrecurrent uterine cervical carcinomas were diagnosed by clinical course. Continuous bladder irrigation was performed 35-55 min after intravenous administration of 185-370 MBq (18)F-FDG, and an emission scan was obtained 40-55 min after intravenous administration. Standardized uptake value (SUV) was used to estimate the degree of (18)F-FDG uptake quantitatively. RESULTS: After bladder irrigation, the (18)F-FDG activity in the urinary tract was eliminated in 33 patients, so that detection of tumor (18)F-FDG accumulation was easy. Two patients showed residual activity in the urinary bladder, and 6 patients showed activity in the ureter. An artifact was seen in 1 patient with residual activity in the urinary bladder caused by insufficient irrigation. However, these residual activities had no influence on detecting (18)F-FDG accumulation in tumor. The mean (+/-SD) of SUVs of malignant lesions was 6.04 +/- 3.22, that of nonmalignant lesions was 1.71 +/- 1.12, and the difference was significant (P = 0.0002). SUVs of all malignant lesions were greater than 2.0, and SUVs of all nonmalignant lesions, except the 1 case of ovarian fibroma, were less than 2.0. CONCLUSION: (18)F-FDG PET with continuous bladder irrigation is useful for eliminating (18)F-FDG activity in the bladder and for differentiating between malignant and nonmalignant uterine or ovarian masses.